sqlalchemy has a storage
[tiramisu.git] / tiramisu / setting.py
index 964ec81..c461d5e 100644 (file)
 # the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
 # the whole pypy projet is under MIT licence
 # ____________________________________________________________
+from time import time
+from copy import copy
+import weakref
+from tiramisu.error import (RequirementError, PropertiesOptionError,
+                            ConstError)
+from tiramisu.i18n import _
 
 
-class _const:
+"Default encoding for display a Config if raise UnicodeEncodeError"
+default_encoding = 'utf-8'
+
+"""If cache and expire is enable, time before cache is expired.
+This delay start first time value/setting is set in cache, even if
+user access several time to value/setting
+"""
+expires_time = 5
+"""List of default properties (you can add new one if needed).
+
+For common properties and personalise properties, if a propery is set for
+an Option and for the Config together, Setting raise a PropertiesOptionError
+
+* Common properties:
+
+hidden
+    option with this property can only get value in read only mode. This
+    option is not available in read write mode.
+
+disabled
+    option with this property cannot be set/get
+
+frozen
+    cannot set value for option with this properties if 'frozen' is set in
+    config
+
+mandatory
+    should set value for option with this properties if 'mandatory' is set in
+    config
+
+
+* Special property:
+
+permissive
+    option with 'permissive' cannot raise PropertiesOptionError for properties
+    set in permissive
+    config with 'permissive', whole option in this config cannot raise
+    PropertiesOptionError for properties set in permissive
+
+* Special Config properties:
+
+cache
+    if set, enable cache settings and values
+
+expire
+    if set, settings and values in cache expire after ``expires_time``
+
+everything_frozen
+    whole option in config are frozen (even if option have not frozen
+    property)
+
+validator
+    launch validator set by user in option (this property has no effect
+    for internal validator)
+"""
+default_properties = ('cache', 'expire', 'validator')
+
+"""Config can be in two defaut mode:
+
+read_only
+    you can get all variables not disabled but you cannot set any variables
+    if a value has a callback without any value, callback is launch and value
+    of this variable can change
+    you cannot access to mandatory variable without values
+
+read_write
+    you can get all variables not disabled and not hidden
+    you can set all variables not frozen
+"""
+ro_append = set(['frozen', 'disabled', 'validator', 'everything_frozen',
+                'mandatory'])
+ro_remove = set(['permissive', 'hidden'])
+rw_append = set(['frozen', 'disabled', 'validator', 'hidden'])
+rw_remove = set(['permissive', 'everything_frozen', 'mandatory'])
+
+
+# ____________________________________________________________
+class _NameSpace(object):
     """convenient class that emulates a module
-    and builds constants (that is, unique names)"""
-    class ConstError(TypeError):
-        pass
+    and builds constants (that is, unique names)
+    when attribute is added, we cannot delete it
+    """
 
     def __setattr__(self, name, value):
         if name in self.__dict__:
-            raise self.ConstError, "Can't rebind group ({})".format(name)
+            raise ConstError(_("can't rebind {0}").format(name))
         self.__dict__[name] = value
 
     def __delattr__(self, name):
         if name in self.__dict__:
-            raise self.ConstError, "Can't unbind group ({})".format(name)
-        raise NameError(name)
+            raise ConstError(_("can't unbind {0}").format(name))
+        raise ValueError(name)
 
 
-# ____________________________________________________________
-class GroupModule(_const):
+class GroupModule(_NameSpace):
     "emulates a module to manage unique group (OptionDescription) names"
     class GroupType(str):
         """allowed normal group (OptionDescription) names
@@ -57,22 +139,9 @@ class GroupModule(_const):
         *master* means : groups that have the 'master' attribute set
         """
         pass
-# setting.groups (emulates a module)
-groups = GroupModule()
 
 
-def populate_groups():
-    "populates the available groups in the appropriate namespaces"
-    groups.master = groups.MasterGroupType('master')
-    groups.default = groups.DefaultGroupType('default')
-    groups.family = groups.GroupType('family')
-
-# names are in the module now
-populate_groups()
-
-
-# ____________________________________________________________
-class OwnerModule(_const):
+class OwnerModule(_NameSpace):
     """emulates a module to manage unique owner names.
 
     owners are living in `Config._cfgimpl_value_owners`
@@ -85,161 +154,495 @@ class OwnerModule(_const):
     class DefaultOwner(Owner):
         """groups that are default (typically 'default')"""
         pass
-# setting.owners (emulates a module)
-owners = OwnerModule()
+
+
+class MultiTypeModule(_NameSpace):
+    "namespace for the master/slaves"
+    class MultiType(str):
+        pass
+
+    class DefaultMultiType(MultiType):
+        pass
+
+    class MasterMultiType(MultiType):
+        pass
+
+    class SlaveMultiType(MultiType):
+        pass
+
+
+# ____________________________________________________________
+def populate_groups():
+    """populates the available groups in the appropriate namespaces
+
+    groups.default
+        default group set when creating a new optiondescription
+
+    groups.master
+        master group is a special optiondescription, all suboptions should be
+        multi option and all values should have same length, to find master's
+        option, the optiondescription's name should be same than de master's
+        option
+
+    groups.family
+        example of group, no special behavior with this group's type
+    """
+    groups.default = groups.DefaultGroupType('default')
+    groups.master = groups.MasterGroupType('master')
+    groups.family = groups.GroupType('family')
 
 
 def populate_owners():
     """populates the available owners in the appropriate namespaces
 
-    - 'user' is the generic is the generic owner.
-    - 'default' is the config owner after init time
+    default
+        is the config owner after init time
+
+    user
+        is the generic is the generic owner
     """
     setattr(owners, 'default', owners.DefaultOwner('default'))
     setattr(owners, 'user', owners.Owner('user'))
 
-    def add_owner(name):
+    def addowner(name):
         """
         :param name: the name of the new owner
         """
         setattr(owners, name, owners.Owner(name))
-    setattr(owners, 'add_owner', add_owner)
-
-# names are in the module now
-populate_owners()
-
-
-class MultiTypeModule(_const):
-    class MultiType(str):
-        pass
+    setattr(owners, 'addowner', addowner)
 
-    class DefaultMultiType(MultiType):
-        pass
 
-    class MasterMultiType(MultiType):
-        pass
+def populate_multitypes():
+    """all multi option should have a type, this type is automaticly set do
+    not touch this
 
-    class SlaveMultiType(MultiType):
-        pass
+    default
+        default's multi option set if not master or slave
 
-multitypes = MultiTypeModule()
+    master
+        master's option in a group with master's type, name of this option
+        should be the same name of the optiondescription
 
+    slave
+        slave's option in a group with master's type
 
-def populate_multitypes():
+    """
     setattr(multitypes, 'default', multitypes.DefaultMultiType('default'))
     setattr(multitypes, 'master', multitypes.MasterMultiType('master'))
     setattr(multitypes, 'slave', multitypes.SlaveMultiType('slave'))
 
+
+# ____________________________________________________________
+# populate groups, owners and multitypes with default attributes
+groups = GroupModule()
+populate_groups()
+owners = OwnerModule()
+populate_owners()
+multitypes = MultiTypeModule()
 populate_multitypes()
 
 
+# ____________________________________________________________
+class Undefined():
+    pass
+
+
+undefined = Undefined()
+
+
+# ____________________________________________________________
+class Property(object):
+    "a property is responsible of the option's value access rules"
+    __slots__ = ('_setting', '_properties', '_opt', '_path')
+
+    def __init__(self, setting, prop, opt=None, path=None):
+        self._opt = opt
+        self._path = path
+        self._setting = setting
+        self._properties = prop
+
+    def append(self, propname):
+        """Appends a property named propname
+
+        :param propname: a predefined or user defined property name
+        :type propname: string
+        """
+        if self._opt is not None and self._opt.impl_getrequires() is not None \
+                and propname in self._opt.impl_getrequires():
+            raise ValueError(_('cannot append {0} property for option {1}: '
+                               'this property is calculated').format(
+                                   propname, self._opt.impl_getname()))
+        self._properties.add(propname)
+        self._setting._setproperties(self._properties, self._opt, self._path)
+
+    def remove(self, propname):
+        """Removes a property named propname
+
+        :param propname: a predefined or user defined property name
+        :type propname: string
+        """
+        if propname in self._properties:
+            self._properties.remove(propname)
+            self._setting._setproperties(self._properties, self._opt,
+                                         self._path)
+
+    def extend(self, propnames):
+        """Extends properties to the existing properties
+
+        :param propnames: an iterable made of property names
+        :type propnames: iterable of string
+        """
+        for propname in propnames:
+            self.append(propname)
+
+    def reset(self):
+        """resets the properties (does not **clear** the properties,
+        default properties are still present)
+        """
+        self._setting.reset(_path=self._path)
+
+    def __contains__(self, propname):
+        return propname in self._properties
+
+    def __repr__(self):
+        return str(list(self._properties))
+
+
 #____________________________________________________________
-class Setting(object):
-    "``Config()``'s configuration options"
-    __slots__ = ('properties', 'permissives', 'owner')
-
-    def __init__(self):
-        # properties attribute: the name of a property enables this property
-        # key is None for global properties
-        self.properties = {None: []}  # ['hidden', 'disabled', 'mandatory', 'frozen', 'validator']}
-        # permissive properties
-        self.permissives = {}
+class Settings(object):
+    "``config.Config()``'s configuration options settings"
+    __slots__ = ('context', '_owner', '_p_', '__weakref__')
+
+    def __init__(self, context, storage):
+        """
+        initializer
+
+        :param context: the root config
+        :param storage: the storage type
+
+                        - dictionary -> in memory
+                        - sqlite3 -> persistent
+        """
         # generic owner
-        self.owner = owners.user
+        self._owner = owners.user
+        self.context = weakref.ref(context)
+        self._p_ = storage
 
     #____________________________________________________________
     # properties methods
-    def has_properties(self, opt=None):
-        "has properties means the Config's properties attribute is not empty"
-        return bool(len(self.get_properties(opt)))
+    def __contains__(self, propname):
+        "enables the pythonic 'in' syntaxic sugar"
+        return propname in self._getproperties()
 
-    def get_properties(self, opt=None):
-        if opt is None:
-            default = []
-        else:
-            default = list(opt._properties)
-        return self.properties.get(opt, default)
+    def __repr__(self):
+        return str(list(self._getproperties()))
+
+    def __getitem__(self, opt):
+        path = self._get_path_by_opt(opt)
+        return self._getitem(opt, path)
 
-    def has_property(self, propname, opt=None):
-        """has property propname in the Config's properties attribute
-        :param property: string wich is the name of the property"""
-        return propname in self.get_properties(opt)
+    def _getitem(self, opt, path):
+        return Property(self, self._getproperties(opt, path), opt, path)
 
-    def enable_property(self, propname):
+    def __setitem__(self, opt, value):
+        raise ValueError('you should only append/remove properties')
+
+    def reset(self, opt=None, _path=None, all_properties=False):
+        if all_properties and (_path or opt):
+            raise ValueError(_('opt and all_properties must not be set '
+                               'together in reset'))
+        if all_properties:
+            self._p_.reset_all_propertives()
+        else:
+            if opt is not None and _path is None:
+                _path = self._get_path_by_opt(opt)
+            self._p_.reset_properties(_path)
+        self.context().cfgimpl_reset_cache()
+
+    def _getproperties(self, opt=None, path=None, is_apply_req=True):
+        if opt is None:
+            props = self._p_.getproperties(path, default_properties)
+        else:
+            if path is None:
+                raise ValueError(_('if opt is not None, path should not be'
+                                   ' None in _getproperties'))
+            ntime = None
+            if 'cache' in self and self._p_.hascache(path):
+                if 'expire' in self:
+                    ntime = int(time())
+                is_cached, props = self._p_.getcache(path, ntime)
+                if is_cached:
+                    return props
+            #FIXME
+            props = self._p_.getproperties(path, opt.impl_getproperties())
+            if is_apply_req:
+                props |= self.apply_requires(opt, path)
+            if 'cache' in self:
+                if 'expire' in self:
+                    if  ntime is None:
+                        ntime = int(time())
+                    ntime = ntime + expires_time
+                self._p_.setcache(path, props, ntime)
+        return props
+
+    def append(self, propname):
         "puts property propname in the Config's properties attribute"
-        props = self.get_properties()
-        if propname not in props:
-            props.append(propname)
-        self.set_properties(props)
+        props = self._p_.getproperties(None, default_properties)
+        props.add(propname)
+        self._setproperties(props, None, None)
 
-    def disable_property(self, propname):
+    def remove(self, propname):
         "deletes property propname in the Config's properties attribute"
-        props = self.get_properties()
+        props = self._p_.getproperties(None, default_properties)
         if propname in props:
             props.remove(propname)
-        self.set_properties(props)
+            self._setproperties(props, None, None)
 
-    def set_properties(self, properties, opt=None):
+    def _setproperties(self, properties, opt, path):
         """save properties for specified opt
         (never save properties if same has option properties)
         """
         if opt is None:
-            self.properties[opt] = properties
+            self._p_.setproperties(None, properties)
         else:
-            if opt._properties == properties:
-                if opt in self.properties:
-                    del(self.properties[opt])
-            else:
-                self.properties[opt] = properties
-
-    def add_property(self, propname, opt):
-        properties = self.get_properties(opt)
-        if not propname in properties:
-            properties.append(propname)
-            self.set_properties(properties, opt)
-
-    def del_property(self, propname, opt):
-        properties = self.get_properties(opt)
-        if propname in properties:
-            properties.remove(propname)
-            self.set_properties(properties, opt)
+            #if opt._calc_properties is not None:
+            #    properties -= opt._calc_properties
+            #FIXME a revoir ---------
+            #if set(opt._properties) == properties:
+            #    self._p_.reset_properties(path)
+            #else:
+            #    self._p_.setproperties(path, properties)
+            self._p_.setproperties(path, properties)
+            #FIXME fin revoir -----
+        self.context().cfgimpl_reset_cache()
 
     #____________________________________________________________
-    def get_permissive(self, opt=None):
-        return self.permissives.get(opt, [])
+    def validate_properties(self, opt_or_descr, is_descr, is_write, path,
+                            value=None, force_permissive=False,
+                            force_properties=None, force_permissives=None):
+        """
+        validation upon the properties related to `opt_or_descr`
+
+        :param opt_or_descr: an option or an option description object
+        :param force_permissive: behaves as if the permissive property
+                                 was present
+        :param force_properties: set() with properties that is force to add
+                                 in global properties
+        :param force_permissives: set() with permissives that is force to add
+                                 in global permissives
+        :param is_descr: we have to know if we are in an option description,
+                         just because the mandatory property
+                         doesn't exist here
+
+        :param is_write: in the validation process, an option is to be modified,
+                         the behavior can be different
+                         (typically with the `frozen` property)
+        """
+        # opt properties
+        properties = copy(self._getproperties(opt_or_descr, path))
+        self_properties = copy(self._getproperties())
+        # remove opt permissive
+        # permissive affect option's permission with or without permissive
+        # global property
+        properties -= self._p_.getpermissive(path)
+        # remove global permissive if need
+        if force_permissive is True or 'permissive' in self_properties:
+            properties -= self._p_.getpermissive()
+        if force_permissives is not None:
+            properties -= force_permissives
+
+        # global properties
+        if force_properties is not None:
+            self_properties.update(force_properties)
+
+        # calc properties
+        properties &= self_properties
+        # mandatory and frozen are special properties
+        if is_descr:
+            properties -= frozenset(('mandatory', 'frozen'))
+        else:
+            if 'mandatory' in properties and \
+                    not self.context().cfgimpl_get_values()._isempty(
+                        opt_or_descr, value):
+                properties.remove('mandatory')
+            if is_write and 'everything_frozen' in self_properties:
+                properties.add('frozen')
+            elif 'frozen' in properties and not is_write:
+                properties.remove('frozen')
+        # at this point an option should not remain in properties
+        if properties != frozenset():
+            props = list(properties)
+            if 'frozen' in properties:
+                raise PropertiesOptionError(_('cannot change the value for '
+                                              'option {0} this option is'
+                                              ' frozen').format(
+                                                  opt_or_descr.impl_getname()),
+                                            props)
+            else:
+                raise PropertiesOptionError(_("trying to access to an option "
+                                              "named: {0} with properties {1}"
+                                              "").format(opt_or_descr.impl_getname(),
+                                                         str(props)), props)
 
-    def set_permissive(self, permissive, opt=None):
-        if not isinstance(permissive, list):
-            raise TypeError('permissive must be a list')
-        self.permissives[opt] = permissive
+    def setpermissive(self, permissive, opt=None, path=None):
+        """
+        enables us to put the permissives in the storage
+
+        :param path: the option's path
+        :param type: str
+        :param opt: if an option object is set, the path is extracted.
+                    it is better (faster) to set the path parameter
+                    instead of passing a :class:`tiramisu.option.Option()` object.
+        """
+        if opt is not None and path is None:
+            path = self._get_path_by_opt(opt)
+        if not isinstance(permissive, tuple):
+            raise TypeError(_('permissive must be a tuple'))
+        self._p_.setpermissive(path, permissive)
 
     #____________________________________________________________
     def setowner(self, owner):
         ":param owner: sets the default value for owner at the Config level"
         if not isinstance(owner, owners.Owner):
-            raise TypeError("invalid generic owner {0}".format(str(owner)))
-        self.owner = owner
+            raise TypeError(_("invalid generic owner {0}").format(str(owner)))
+        self._owner = owner
 
     def getowner(self):
-        return self.owner
+        return self._owner
 
     #____________________________________________________________
+    def _read(self, remove, append):
+        for prop in remove:
+            self.remove(prop)
+        for prop in append:
+            self.append(prop)
+
     def read_only(self):
-        "convenience method to freeze, hidde and disable"
-        self.enable_property('everything_frozen')
-        self.enable_property('frozen')  # can be usefull...
-        self.disable_property('hidden')
-        self.enable_property('disabled')
-        self.enable_property('mandatory')
-        self.enable_property('validator')
-        self.disable_property('permissive')
+        "convenience method to freeze, hide and disable"
+        self._read(ro_remove, ro_append)
 
     def read_write(self):
-        "convenience method to freeze, hidde and disable"
-        self.disable_property('everything_frozen')
-        self.enable_property('frozen')  # can be usefull...
-        self.enable_property('hidden')
-        self.enable_property('disabled')
-        self.disable_property('mandatory')
-        self.disable_property('validator')
-        self.disable_property('permissive')
+        "convenience method to freeze, hide and disable"
+        self._read(rw_remove, rw_append)
+
+    def reset_cache(self, only_expired):
+        """reset all settings in cache
+
+        :param only_expired: if True reset only expired cached values
+        :type only_expired: boolean
+        """
+        if only_expired:
+            self._p_.reset_expired_cache(int(time()))
+        else:
+            self._p_.reset_all_cache()
+
+    def apply_requires(self, opt, path):
+        """carries out the jit (just in time) requirements between options
+
+        a requirement is a tuple of this form that comes from the option's
+        requirements validation::
+
+            (option, expected, action, inverse, transitive, same_action)
+
+        let's have a look at all the tuple's items:
+
+        - **option** is the target option's
+
+        - **expected** is the target option's value that is going to trigger
+          an action
+
+        - **action** is the (property) action to be accomplished if the target
+          option happens to have the expected value
+
+        - if **inverse** is `True` and if the target option's value does not
+          apply, then the property action must be removed from the option's
+          properties list (wich means that the property is inverted)
+
+        - **transitive**: but what happens if the target option cannot be
+          accessed ? We don't kown the target option's value. Actually if some
+          property in the target option is not present in the permissive, the
+          target option's value cannot be accessed. In this case, the
+          **action** have to be applied to the option. (the **action** property
+          is then added to the option).
+
+        - **same_action**: actually, if **same_action** is `True`, the
+          transitivity is not accomplished. The transitivity is accomplished
+          only if the target option **has the same property** that the demanded
+          action. If the target option's value is not accessible because of
+          another reason, because of a property of another type, then an
+          exception :exc:`~error.RequirementError` is raised.
+
+        And at last, if no target option matches the expected values, the
+        action must be removed from the option's properties list.
+
+        :param opt: the option on wich the requirement occurs
+        :type opt: `option.Option()`
+        :param path: the option's path in the config
+        :type path: str
+        """
+        if opt.impl_getrequires() is None:
+            return frozenset()
+
+        # filters the callbacks
+        calc_properties = set()
+        for require in opt.impl_getrequires():
+            expected = tuple(require.get_expected())
+            inverse = require.inverse
+            option = require.option
+            reqpath = self._get_path_by_opt(option)
+            if reqpath == path or reqpath.startswith(path + '.'):
+                raise RequirementError(_("malformed requirements "
+                                         "imbrication detected for option:"
+                                         " '{0}' with requirement on: "
+                                         "'{1}'").format(path, reqpath))
+            try:
+                value = self.context()._getattr(reqpath,
+                                                force_permissive=True)
+            except PropertiesOptionError as err:
+                if not require.transitive:
+                    continue
+                properties = err.proptype
+                if require.same_action and require.action not in properties:
+                    raise RequirementError(_("option '{0}' has "
+                                             "requirement's property "
+                                             "error: "
+                                             "{1} {2}").format(opt.impl_getname(),
+                                                               reqpath,
+                                                               properties))
+                # transitive action, force expected
+                value = expected[0]
+                inverse = False
+            if not inverse and value in expected or \
+                    inverse and value not in expected:
+                calc_properties.add(require.action)
+                # the calculation cannot be carried out
+                #break
+        return calc_properties
+
+    def _get_path_by_opt(self, opt):
+        """just a wrapper to get path in optiondescription's cache
+
+        :param opt: `Option`'s object
+        :returns: path
+        """
+        return self.context().cfgimpl_get_description().impl_get_path_by_opt(opt)
+
+    def get_modified_properties(self):
+        return self._p_.get_modified_properties()
+
+    def get_modified_permissives(self):
+        return self._p_.get_modified_permissives()
+
+    def __getstate__(self):
+        return {'_p_': self._p_, '_owner': str(self._owner)}
+
+    def _impl_setstate(self, storage):
+        self._p_._storage = storage
+
+    def __setstate__(self, states):
+        self._p_ = states['_p_']
+        try:
+            self._owner = getattr(owners, states['_owner'])
+        except AttributeError:
+            owners.addowner(states['_owner'])
+            self._owner = getattr(owners, states['_owner'])